与杭电的max sum plus plus相同。

我用那个代码,把m改成2上交就ac了(两个字段)

代码如下:

#include<stdio.h>
#include<stdlib.h>
 
int maxsum(int e[], int n, int m)
{
       int *curr_best;
       int *prev_best;
       int max_sum, i, j;
 
       curr_best = (int*)malloc(sizeof(int) * (n + 1));//分配,不初始化
       prev_best = (int*)calloc(n + 1, sizeof(int));//分配,且每个元素初始化为0
 
       *curr_best = 0;
       e--;
 
       for(i = 1; i <= m; ++i)
       {
              max_sum = -2147483648;
              for(j = i; j <= n; ++j)
              {
                     if(curr_best[j - 1] < prev_best[j - 1])//prev_best中存放的是i-1阶段的最大值
                            curr_best[j] = prev_best[j - 1] + e[j];
                     else
                            curr_best[j] = curr_best[j - 1] + e[j];
                     prev_best[j - 1] = max_sum;
                     if(max_sum < curr_best[j])
                            max_sum = curr_best[j];//prev_best中存放i阶段的最大值
              }
              prev_best[j - 1] = max_sum;//对第n个数赋值
       }
 
       free(prev_best);
       free(curr_best);
 
       return max_sum;
}
int main()
{
 int i,n;
 int *data;
 while(scanf("%d",&n),n)
 {
  data=(int *)malloc(sizeof(int)*n);
  for(i=0;i<n;i++)
   scanf("%d",&data[i]);
  printf("%d\n",maxsum(data,n,2));
  free(data);
 }
 return 0;
}

posted on 2008-11-08 23:02  pandy  阅读(197)  评论(0编辑  收藏  举报